Outage probability analysis in power-beacon assisted energy harvesting cognitive relay wireless networks

We study the performance of the secondary relay system in a power-beacon (PB) assisted energy harvesting cognitive relay wireless network. In our system model, a secondary source node and a relay node first harvest energy from distributed PBs. Then, the source node transmits its data to the destination node with the help of the relay node. Also, fading coefficients of the links from the PBs to the source node and relay node are assumed independent but not necessarily identically distributed (i.n.i.d) Nakagami- random variables. We derive exact expressions for the power outage probability and the channel outage probability. Based on that, we analyze the total outage probability of the secondary relay system. Asymptotic analysis is also performed, which provides insights into the system behavior. Moreover, we evaluate impacts of the primary network on the performance of the secondary network with respect to the tolerant interference threshold at the primary receiver as well as the interference introduced by the primary transmitter at the secondary source and relay nodes. Simulation results are provided to validate the analysis

On the optimal user grouping in NOMA system technology

This paper provides a state-of-art analysis of the most relevant studies on optimal user-aggregation strategies for non-orthogonal multiple access (NOMA) technology. The main ideas behind are i) to highlight how, in addition to the adoption of an optimal power allocation scheme, an optimal user-aggregation strategy represents an important key factor for improving NOMA system performance, and ii) to provide an exhaustive survey of the most relevant studies which can serve as useful starting point for the definition of new channel state-aware user-aggregation strategies for NOMA systems which, at the time of writing, represents a research field that still remains to be investigated more in depth. A detailed and complete analysis, which permits to point out the need to guarantee a certain relationship between users’ channel gain, is provided for each cited work

Throughput analysis of power-beacon-assisted energy harvesting wireless systems over non-identical Nakagami-m fading channels

We consider a distributed power-beacon (PB)- assisted wireless powered communication network that consists of multiple PBs, multiple transmitters, and one receiver. The transmitters harvest energy from the PBs, and then transmit their individual data to the receiver via time division multiple access. Fading coefficients of channels between nodes are assumed independent but not necessarily identically distributed Nakagamim random variables. We derive an exact expression for the achievable throughput. A closed-form approximated expression of the throughput in the high signal-to-noise ratio regime is obtained. Moreover, we proposed the optimal time allocation method to maximizing the sum throughput of the whole system. Our analysis is corroborated by Monte Carlo simulations

Performance analysis of NOMA short-packet communications With QoS-based SIC detecting order

In this letter, we perform an unified analysis of an uplink non-orthogonal multiple access (NOMA) system with short-packets over a wide range of fading channels, such as lognormal-Nakagami-m, generalized KG, η − μ, Nakagami-q (Hoyt), κ − μ, Rician, Nakagami-m, and Rayleigh fading. The system model consists of a high-priority user with low-rate, low-latency and high-reliability requirements, and a low-priority user with high-rate and delay-tolerant. We first derive closed-form expressions of the average block error-rate (BLER) and the asymptotic at the high signal-to-noise ratio (SNR) regime. Next, we optimize the power back-off level and the packet-length to maximize the throughput of the low-priority user subject to the quality-of-service (QoS) requirements of the high-priority user. Theoretical analysis is corroborated by simulation results

Throughput analysis of energy harvesting MIMO relay systems over Nakagami-m fading channels

In this paper, we consider two-hop multi-input multi-output (MIMO) relay wireless systems with energy harvesting. In each hop, transmit antenna selection (TAS)/receive antenna selection (RAS), TAS/maximum ratio combining (MRC), or maximum ratio transmission (MRT)/RAS is employed. Also, a relay harvests energy from the source via either a time switching-based relaying protocol (TSR) or a power splitting-based relaying protocol (PSR). We perform unified analysis of the resulting eighteen system configurations over Nakagami-m fading channels. Specifically, we derive exact and approximated closed-form expressions for ergodic capacity and throughput. Moreover, optimal energy-harvesting time (in TSR-based system) and optimal power-splitting ratio (in PSR-based system) to achieve maximum throughput at high signal-to-noise-ratio (SNR) are analyzed. Impacts of various MIMO processing schemes and energy harvesting mechanisms on the system performance are also examined and discussed. The theoretical analysis is corroborated by simulations

Unified analysis of energy harvesting-based MIMO relay wireless systems over Nakagami-m fading channels

In this paper, we consider two-hop multi-input multi-output relay wireless systems with energy harvesting. In each hop, transmit antenna selection/receive antenna selection, transmit antenna selection/maximum ratio combining, or maximum ratio transmission/receive antenna selection is used. Also, an energy-constrained relay harvests energy from the source via either a time switching–based relaying protocol or a power splitting–based relaying protocol. We perform unified analysis of the systems over Nakagami-m fading channels. Specifically, we derive exact closed form expressions for ergodic capacity and throughput (for delay-tolerant transmission mode) and outage probability and throughput (for delay-limited transmission). Optimal energy-harvesting time (in time switching–based relaying protocol–based system) and optimal power-splitting ratio (in power splitting–based relaying protocol–based system) to achieve maximum throughput at high signal-to-noise-ratio are also determined. Moreover, we derive an exact closed form expression for the bit error rate, which facilitates the evaluation of the system performance. Impacts of various multi-input multi-output processing schemes, numbers of equipped antennas, energy-harvesting mechanisms, and transmission modes on the system performance are also examined and discussed. All theoretical analyses are corroborated by simulations